The present invention relates generally to the field of wheel chairs, and, more specifically to brake systems which allow the safe operation thereof.
At the present state-of-the-art, almost all wheelchairs use a locking lever system in which a wheelchair user must remember to lock both wheels of the wheel chair before attempting to rise or before being transferred with the help of an ambulatory party such as a nurse. If the patient or helper doesn't remember to lock the brakes, the wheel chair may roll backward and injure the patient who may then fall. Depending upon the slope of the surface upon which the wheelchair is located, the wheelchair may freewheel away and be lost or damaged. Patients often forget to set the brakes because of mental infirmities brought on by old age, due to drug induced drowsiness, or because of other pre-occupations. Some patients are also unable to operate side-mounted levers because of physical infirmities such as quadriplegia and hemiplegia.
A number of inventions have been proposed to deal with this problem. For example, H. M. Eagelson, Jr. et. al. (U.S. Pat. No. 3,302,757) provided an automatic immobilizing device; H. E. Marshall (U.S. Pat. No. 3,529,700) provided a brake assembly for wheelchairs; and R. E. Knoche (U.S. Pat. No. 4,350,227) provided a wheelchair brake assembly; however, none of the referenced inventions provides the fully automatic operation and safety features addressed by the present invention.